The demand to protect the sensitive and valuable data transmitted from satellites to ground has increased and hence the need to use security algorithm on board in Earth Observation satellites also increased. The security algorithms like Advanced Encryption Standard by NIST (National Institute of Standards and Technology), is popular in the aerospace industry including satellites. The analysis of the effects of Single Even Upsets (SEUs) on imaging data during on-board encryption is detailed. To avoid data corruption due to SEUs, fault-tolerant model of OFB mode encryption based on robust error detection and corrections codes is proposed. The satellite imaging data is encrypted using OFB mode encryption is done using Matlab.